1. Technical Field
The present invention relates to an audio system for reproducing information recorded on a medium such as music or the like, in particular relates to an audio system suitable for portable purpose.
2. Description of the Related Art
This application claims benefit of priority under 35USC§119 to Japanese Patent Application No. HEI 11-152952, filed on May 31, 1999 the entire contents of which are incorporated by reference herein.
In general, a portable audio system, as shown in FIGS. 1 and 2, with a small reproducing unit 103 or 104 mountable a memory medium such as a memory card 101 or a cassette tape 102, reads for instance music information recorded on a mounted memory medium. The read music information is transmitted from the reproducing unit 103 or 104 through a connecting cord 105 to a headphone 106. Thereby, with the headphone 106, music can be heard.
Recently, as disclosed in Japanese Patent Application No. HEI 5-39167 (Japanese Patent Laid-open Application (KOKAI) No. HEI 6-251080), there is a wireless audio system. That is, the wireless audio system reads music information or the like of a memory card mounted on a reproduction unit to generate audio signal. The audio signal is FM transmitted from the reproduction unit side to a headphone side.
Further, an audio system disclosed in Japanese Patent Application No. HEI 6-139244 (Japanese Patent Laid-open Application (KOKAI) No. HEI 8-9483) can download audio data to a memory module such as a memory card or the like disposed to a headphone. The respective operation buttons including a play button of audio data or a volume control button or the like are disposed to the headphone itself. Thus, an audio system is constituted of the headphone alone.
However, the aforementioned audio system has the following problems. That is, the audio system disclosed in Japanese Patent Application No. HEI 5-39167 transmits FM audio signal. Accordingly, a transmitter/receiver circuit becomes complicated which necessarily results in higher costs. Further, FM-transmission of the audio signal necessarily invites a deterioration of sound quality and, if there is a user using a similar audio system in the neighborhood, there may be problems with radio interference.
Further, since the audio system disclosed in Japanese Patent Application No. HEI 6-139244 is constituted of a single headphone, each operation button is also mounted on the headphone itself. Accordingly, in the audio system, a user, when hearing sound, namely when wearing a headphone on his or her head, can not see various kinds of operation buttons. As a result, there is a problem of a difficulty in executing various kinds of operations for instance such as volume control, play stop or the like. In addition, in the audio system of this type, being short of display function or the like, there is no way to easily check memory remains of the memory card or the like and a file number showing an order of music or the like. Accordingly, there is also a problem of convenience.